Refrigerating apparatus



Nov. 10, 1931. F. J. NATWlCK ET AL 1,831,256

REFRIGERATING APPARATUS Filed Feb. 11. 1928 Patented Nov. 10, 1931 UNITED STATES PATENT OFFICE FRANK J. NATWICK AND OTTO G. TINKEY, OF PITTSBURGH, PENNSYLVANIA.

mmennarme arraa'arus Application filed iebruary 11, 1928. Serial No. 253,684.

Our invention relates to refrigerating apparatus and particularly to the regulation of cooling coils exposed to large bodies of fluid subject to wide variations in temperature, or

directly to open air. In cooling large spaces and in operating cooling coils in the form of signs exposed to the open air, wide variations in the temperature of the surrounding medium are encountered. In smaller spaces, such as in refrigerators, a smaller temperature change is experienced, although the invention is applicable to such refrigerating apparatus. Many types of thermostatic regulators have been suggested for controlling and varying the passage of a refrigerant through such coils, and the present invention may be used alone or in combination therewith. v

In refrigerating signs it is very important that the cooling coil be operated continuously to always present a frosted surface.

We provide a refrigerating apparatus that is initially adjusted to supply the cooling coil with enough refrigerant to keep it prop-' erly cooled when subjected to the maximum a temperature under which it is to operate.

However, during the seasonal and daily fluctuations of the surrounding mediums, the

amount of refrigerant that is volatilized I .while traversing the cooling coil varies. Any 0 unvolatilized refrigerant remaining in the coil is liable to be carried over to the compressor. If a large body ofliquidaccumulates in the compressor, a liquid head is formed that is liable to blow the head off the coma pressor. It is necessary to make the provision for volatilizing any excess of the liquid refrigerant that may traverse the sign or coil before it reaches the compressor. To accomplish this result we discharge the 40 refrigerant, both liquid and gaseous, from the cooling coil to the compressor through a conductor that is in thermo-conductive engagement with the conductor returning the refrigerant from the compressor and con- 5 denser to the admission valve. During the passage of the refrigerant from the cooling coil to the compressor, any of it remaining in a liquid state-isvolatilized by heat extracted from the refrigerant returning from the condenser. v

The foregoing arrangement produces an operating economy'of the refrigerating device by reducing the amount of water, or other cooling medium, applied to the condensing coils or by permitting the operation of the compressor at a lower pressure, as the refrigtrolling the entrance of a liquid refrigerant into the cooling coil 2. The refrigerant is discharged from the cooling coil 2 through a conductor 5 to a compressor 6. From the compressor 6 the refrigerant traverses a condensing coil 7 and a conductor 8 that is in thermo-conductive relation to the conductor 5.

In the present embodiment of our invention, thermo-conductive relation between the conductors 5 and 8 is obtained by passing the conductor 8 through the conductor 5. However, ,it is to be understood that thermo-conductivity between the conductors 5 and 8 may be obtained by other means. The conductor 8 discharges the refrigerant into a reservoir 9 that is connected by a conductor "10 to the admission valve 4.

In the operation of the refrigerating apparatus the admission valve 4 is set to deliver the proper quantity of liquid refrigerant to the cooling coil 2 under the maximum tem perature conditions to which the latter is subjected. The refrigerant, in traversing the cooling coil 2 is volatilized in accordance with thetemperature surrounding it at any given time.- If the temperature of the surrounding atmosphere is low, only a portion of the refrigerant will be volatilized and the remaining refrigerant will pass into the conductor 5 in its liquid state where it is heated by the refrigerant traversing the conductor 8.

The area of thermo-conductive engagement between the conductors 5 and 8 is such 10.

that a sufiicient amount of heat is extracted from the refrigerant traversing the conductor 8 to volatilize all the liquidrefrigerant in the conductor 5 before reachin the compressor 6. Thisconstruction avoids any danger of a liquid head being formed in the compressor 6 /with the liability of blowing off the compressor head.

The refrigerant is discharged from the compressor 6 to condensing coils 7 cooled by the passage of a cooling medium, either air or water, therethrou h, as is well understood in the art. The refrigerant leaving the condenser traverses the conductor 8 thereby de- 16 livering to the refrigerant traversing the conductor 5 a suflicient amount of heat to volatilize such refrigerant in the liquid state as may be traversing the latter.

The provision of a heat exchange between 6 the fluid traversing the conductors 5 and 8 permits the compressor 6 to be operated at a lower pressure, or with a smaller volume of a cooling medium in engagement with condenser 7'. The refrigerant stored in the res- 25 ervoir 9 is under pressure from the compressor 6tand the capacity of reservoir 9 should be such as to accommodate substantially the entire volume of the refrigerant in the condenser. The refrigerant moves from the reservoir 9 through the admission valve 4 as controlled by the valve.

While we have illustrated and described the present preferred embodiment of ur invention, it is to be understood that various v 35 changes may be made in the invention without departing from the scope of the appended claim.

We claim: A refrigerating system comprising a como pressor, condenser, heat exchanger, receiver, I and an exposed evaporator adapted to be normally frosted its entire length connected in series in the order named, the discharge end of the evaporator being connected through the heat exchanger to the compressor, the -condenser, evaporator and heat exchanger being so proportioned that unevaporated refrigerant from the evaporator will act to supplement the condenser and will be pre- 5 vented from reaching the compressor.

In testimony whereof we have hereunto set I our hands.

FRANK J. NATWICK. OTTO G. TINKEY. 

